whats the best engine for a 87-93 GT?

i have ridden in a 347 87 gt and it was fricking awsome, i was just wondering what is the best route to go and it looks like a stroked 351 that would be a 408 is the best im just curiuos how much it woudl run after you got the engine built, installed, and what kinda suspension and tranny you would need to put in and how much that would be.
 
what about the milage of the car, for someone looking to get a 87-93 stang that plans on putting a stroker into it, does it mater how many miles are on it if your just going to take the engine out? what do you guys recomend on that?